Transplantation of human mesenchymal stem cells into the cisterna magna and its neuroprotective effects in a parkinsonian animal model

Parkinson’s disease (PD) is one of the most common neurodegenerative diseases in the elderly, and therefore, the demand for effective therapies against PD has greatly increased. Therapeutic applications of stem cells have been considered to be one of the promising approaches in PD therapy. In the present study, the neuroprotective effects of hMSCs were evaluated in a parkinsonian rat model. The animal model was established by injecting 6-hydroxydopamine into the striatum of rats. Two weeks later, cultured hMSCs were transplanted into the cisterna magna. We subsequently identified changes in the expression of inflammatory cytokines, neurotrophic factors, microglial activation, and the survival rate of dopaminergic neurons in SNc. Behavioral recovery was also examined. The results indicated that hMSC transplantation increased the expression of anti-inflammatory cytokines as well as neurotrophic factors, and decreased the number of activated microglia. Compared to the sham-grafted group, relatively large numbers of TH-positive neurons were found in the ipsilateral SNc, and amphetamine-induced asymmetrical rotation was significantly reduced after hMSC transplantation. These findings suggest that hMSCs might be neuroprotective, probably through up-regulation of neurotrophic factors and anti-inflammatory cytokines, and this could have a functional impact in reversing PD symptoms.